SELECTIVITY OF INSECTICIDES TO NATURAL ENEMIES ON SOIL CULTIVATED WITH COTTON

Abstract

The objective of this research was to evaluate the selectivity of the most used insecticides for controlling Aphis gossypii Glover, 1877, on natural enemies occurring on the cotton crop soil, under field conditions. The study was conducted in Dourados, Mato Grosso do Sul State, Brazil, as randomized blocks, with seven treatments and four replications. The treatments were: Acetamiprid 200 PS, Carbosulfan 400 CE, Diafentiurom 500 PM, Tiametoxam 250 WG, Imidacloprid 200 SC, Paration Metil 600 CE, and control. The samplings of cotton pests natural enemies occurring in the area were made with ";modified pittfall"; traps. During the evaluation period, it was verified the presence of natural enemies, mainly Araneae (31%), Formicidae (29%), and Tachinidae (16%). The insecticide Acetamiprid 200 PS was not selective to the family Formicidae, but it was selective to Araneida and Tachinidae. The insecticide Tiametoxam 250 WG represented a larger effect in the first day (DAA) to the families Formicidae and Tachinidae, when mortality rates of 100% and 56%, respectively, were observed, but it was selective to Arachnida. The insecticide Imidacloprid 200 SC was not selective to ants and Tachinidae, but it was selective to the occurring spiders. Carbosulfan 400 CE was selective to spiders. Paration Metil 600 CE only preserved populations of Araneida.

KEY-WORDS: Predator; parasitoid; Gossypium hirsutum.